A microbial consortium and leaching process for uranium and associated metal leaching

Abstract

The present application relates to a kind of for uranium and associated metal leaching microbial combination and leaching method.A kind of for uranium and associated metal leaching microbial combination, comprising: oxidation trigger unit: iron cycle microorganism and hydrogen peroxide producing bacteria;Bioleaching unit: acid-producing complexing microorganism, surfactant producing bacteria and brick red microbacterium XS6-1.A kind of for uranium and associated metal leaching method, comprising first inoculating iron cycle microorganism and hydrogen peroxide producing bacteria and reacting 2-6h, form oxidation trigger environment;Then inoculate acid-producing complexing microorganism;Again interval 2-4h, inoculate surfactant producing bacteria;Again interval 0.5-3h, inoculate brick red microbacterium XS6-1 and carry out leaching reaction.The present application is by strain type, proportion, order and time interval are cooperated to limit, construct "oxidation trigger-leaching amplification" biological synergic system, suitable for the green development of complex low-grade co-associated uranium mineral resources.

Description

Technical Field

[0001] This invention belongs to the field of biometallurgical technology, and particularly relates to a microbial combination and leaching method for leaching uranium and associated metals. Background Technology

[0002] Traditional hydrometallurgical processes for uranium ore mainly employ acid leaching or alkaline leaching chemical leaching methods, typically in conjunction with strong oxidizing agents (such as MnO2, NaClO3, Fe). 3+ Chemical leaching (CFLAC) is used to oxidize and dissolve U(IV) into U(VI) using reagents such as H2O2. While this type of process has advantages such as fast reaction rate and mature technology, it still has the following problems: high reagent consumption and high operating costs; high acidity and high salt content in the tailings, making subsequent treatment complex and posing a high environmental risk; for complex associated minerals (such as U-Mo, U-Cu, U-Co, U-REE, etc.), due to significant differences in the redox potential, complexation behavior, and precipitation conditions of different metals, it is difficult to achieve synergistic and efficient leaching of multiple metals; in the treatment of low-grade or difficult-to-leach ores, the chemical leaching efficiency decreases significantly, limiting resource utilization.

[0003] In recent years, bioleaching technology has been considered a green and low-energy alternative technology because it can produce organic acids, redox-active substances, and complexing agents through microbial metabolism, thereby achieving mineral structure destruction and metal dissolution under mild conditions. However, single biological systems also have the following technical bottlenecks: the direct oxidation capacity of microorganisms for U(IV) is limited; the electron transfer rate is slow, resulting in a long leaching cycle; metabolic inhibition or uneven selective dissolution is prone to occur in complex multi-metal systems; and the system stability is greatly affected by environmental factors (pH, Eh, metal toxicity).

[0004] Therefore, it is necessary to construct a multi-species synergistic oxidation leaching system. By introducing a mild and controllable biological oxidant as a "reaction trigger source," the system can, while maintaining environmental friendliness, increase its redox potential (Eh), promote the enhanced metabolic activity of leaching microorganisms, accelerate the conversion of U(IV) to U(VI), and achieve the synergistic leaching of uranium and associated metals. Summary of the Invention

[0005] In view of this, the present invention provides a microbial combination and leaching method for uranium and associated metal leaching. By introducing a mild bio-oxidant (i.e., oxidation-triggered microorganism) into the microbial leaching system as a "fuze" for the leaching reaction, a controllable synergistic oxidation environment is constructed, thereby increasing the redox potential of the system and promoting the metabolic activity of subsequent bioleaching microorganisms. This achieves a dual optimization of reaction rate enhancement and ecological safety without significantly increasing the environmental load.

[0006] This invention provides a microbial assemblies for uranium and associated metal leaching, comprising: Oxidation triggering unit: iron-cycling microorganisms and hydrogen peroxide-producing bacteria; Bioleaching unit: acid-producing-complexing microorganisms, surfactant-producing bacteria, and specific uranium-recognizing-oxidizing reddish-brown microbacterium XS6-1. The ratio of the amount of the iron-circulating microorganism, the hydrogen peroxide-producing bacteria, the acid-complexing microorganism, the surfactant-producing bacteria and the brick-red microbacterium XS6-1 is (0.5-3):(0.5-3):(1-5):(1-5):(1-5).

[0007] Among them, iron-cycling microorganisms can drive Fe 2+ / Fe 3+ The redox cycle between them increases the redox potential of the system; the hydrogen peroxide-producing bacteria continuously release low concentrations of H2O2 during metabolism, which reacts with Fe. 2+ The collaborative formation of the bio-Fenton reaction creates a mild reactive oxygen species (ROS) environment within the system, thereby achieving initial oxidative activation of the mineral structure and creating favorable conditions for subsequent bioleaching processes.

[0008] Preferably, the iron-circulating microorganism is one or more of the following: Dietrichia coli, Dietrichia coli, Ironsporium gancis, Thiobacillus, Leptospira, Ironsporium, Acidobacterium, and Bacillus sulfide.

[0009] Preferably, the hydrogen peroxide producing bacteria is one or more of Lactobacillus, Streptococcus, Staphylococcus, Hydrogenophilic bacteria, and Vibrio violaceus.

[0010] Preferably, the acid-producing complexing microorganism is one or more of the following: *Arthrobacter*, *Amycosis*, *Cladosporium*, *Morchella*, *Penicillium*, *Streptococcus*, *Pandora*, and *Massezia*.

[0011] Preferably, the surfactant-producing bacteria are one or more of the following: Gordonella, Tsukumura, Ustilago maydis, Trichomonas vaginalis, Agrobacterium, Sphingosine monoclonal, Oligotrophoblastus, Rifonsone bacillus, and Mycobacterium.

[0012] The present invention also provides a method for leaching uranium and associated metals, which utilizes any of the above-mentioned combinations of microorganisms for leaching to obtain uranium and associated metals.

[0013] Preferably, the leaching method includes the following steps: Step 1: Crush the ore containing uranium and associated metals to a particle size of 0.5-10 mm; Step 2: Inoculate the ore with a bacterial solution containing the oxidation triggering unit, wherein the oxidation triggering unit includes the iron-circulating microorganisms and the hydrogen peroxide-producing bacteria, and pre-react for 2-6 hours to form an oxidation triggering environment; Step 3: After the redox potential of the system increases, add the bacterial solution containing the bioleaching unit to the reaction system. First, add the acid-producing-complexing microorganism and react for 2-4 hours. Then, inoculate the surfactant-producing bacteria and continue the reaction for 0.5-3 hours. Finally, inoculate the brick-red microbacterium XS6-1. Step 4: Maintain the pH of the system at 2.0-7.0 and the temperature at 15-40℃, and carry out the leaching reaction for 2-15 days.

[0014] The beneficial effects of this invention include: This invention utilizes the synergistic effect of an oxidation-triggered microbial system and a bioleaching microbial system to synergistically limit the types, proportions, sequences, and time intervals of microbial species, thereby constructing a stable and efficient redox regulation system within the system. This system is suitable for addressing the technical bottleneck of complex associated uranium deposits where the metal occurrence states are diverse and the leaching process is difficult.

[0015] The multi-species synergistic leaching system of this invention includes the synergistic effect of oxidation-triggered microorganisms and bioleaching microorganisms. The oxidation-triggered microorganisms include iron-cycling microorganisms and hydrogen peroxide-producing bacteria. Iron-cycling microorganisms: capable of driving Fe... 2+ / Fe 3+ The redox cycle between them increases the redox potential (Eh) of the system; hydrogen peroxide producing bacteria: continuously produce low concentrations of H2O2 during metabolism, which reacts with Fe. 2+ The collaborative formation of a bio-Fenton reaction creates a mild reactive oxygen species (ROS) environment within the system, thereby initiating oxidative activation of the mineral structure, promoting the conversion of U(IV) to U(VI) in uranium minerals, and establishing favorable oxidative conditions for subsequent bioleaching processes. After the formation of the oxidative-triggered environment, the microorganisms in the bioleaching unit further exert their influence.

[0016] During the oxidation-triggered phase, iron-cycling microorganisms and hydrogen peroxide-producing bacteria do not function independently, but rather through Fe... 2+ / Fe 3+ The circulation of iron, the release of low-concentration H2O2, and the generation of reactive oxygen species together constitute a mild biological Fenton reaction system. Its mechanism of action can be summarized as follows: iron-circulating microorganisms promote the exchange of Fe(III) minerals or Fe in the solution. 3+ A reduction transformation occurs, producing Fe. 2+ Hydrogen peroxide-producing bacteria continuously release low concentrations of H2O2 during their metabolism; Fe 2+ It reacts with H2O2 to produce Fe 3+and hydroxyl radical •OH; Fe 3+ H₂O₂ and •OH can all participate in the oxidation of U(IV), converting the sparingly soluble U(IV) into the more easily complexed and migrated U(VI). Meanwhile, Fe… 2+ Iron is re-oxidized or participates in the cyclic reaction under the action of iron-circulating microorganisms, thus maintaining the system's continuous oxidation-initiating ability. The reaction process can be represented as follows: Fe(III) 矿物结构 + Iron cycling microorganisms → Fe 2+ (Mineral reduction and dissolution) Hydrogen peroxide producing bacteria → H2O2 (H2O2 is produced by microbial metabolism). Fe 2+ + H2O2→Fe 3+ + •OH (strong oxidizing agent) + OH - , Fe 3+ + U(IV) → Fe 2+ + U(VI)(Fe 3+ U(IV) oxide), H2O2+ U(IV) → H2O + U(VI) (H2O2 oxidizes U(IV)), •OH + U(IV) → H2O+ U(VI) (•OH oxidizes U(IV)), Fe 2+ + Iron cycling microorganisms → Fe 3+ .

[0017] Through the above cycle, the leaching system can rapidly increase the redox potential without the addition of strong acids and strong oxidants, and establish a mild, continuous and controllable oxidation environment at the mineral interface, providing a reaction basis for subsequent bioleaching scale-up.

[0018] Acid-producing and complexing microorganisms: secrete organic acids (oxalic acid, citric acid, gluconic acid, succinic acid, malic acid, etc.) and metal complexing ligands to disrupt mineral crystal structures and complex metal ions, thereby promoting the release of metals from the mineral crystal lattice; through complexing Fe... 2+ / Fe 3+ Inhibits iron ion hydrolysis and precipitation, maintains Fe 2+ / Fe 3+The recycling process enhances the continuous activation capacity of the bio-Fenton system for the uranium-polymetallic ore interface. Furthermore, organic complexing ligands can delay the non-selective decomposition of H2O2 generated by hydrogen peroxide-producing bacteria, maximizing the redox potential of the system at low doses of H2O2 in the oxidation triggering unit. Surfactant-producing bacteria secrete surfactants (rhamnolipids, phycolipids, sophorol, etc.) to reduce interfacial tension in the ore, increasing the permeability of the leachate to ore pores and microfractures, and enhancing the contact efficiency between the ore and the solution. Specific uranium recognition-oxidation microorganisms, namely *Bacillus rubrum* XS6-1, are used to specifically recognize uranium minerals, specifically capturing or adsorbing around them, efficiently oxidizing and leaching uranium (promoting the oxidation of U(IV) to U(VI)) and associated mineral resources. Through the synergistic effect of these multifunctional microorganisms, a stable oxidation-complexation-interface enhancement microenvironment is formed on the mineral surface, thereby achieving efficient synergistic leaching of uranium and its associated metal resources.

[0019] The leaching method of this invention is based on a biological synergistic mechanism of "oxidation triggering-leaching scale-up". A mild biological oxidant (i.e., oxidation triggering unit microorganism) is introduced into a multi-strain synergistic leaching system as a synergistic oxidation trigger source to drive Fe... 2+ / Fe 3+ The system circulates and generates H2O2, creating a mild and stable oxidizing environment that increases the system's redox potential (Eh), thereby enhancing the metabolic activity of subsequent leaching microorganisms and achieving synergistic leaching of multi-metal resources. The technical effects are as follows: 1. Significantly improves oxidation triggering rate: Through the preferential action of iron-cycling microorganisms and hydrogen peroxide-producing bacteria, Fe can be rapidly established in the early stages of the reaction. 2+ / Fe 3+ The circulating and low-dose H2O2 reactive oxygen environment increases the system's Eh to 200-650 mV, which is conducive to the conversion of U(IV) to U(VI), overcoming the problems of long induction period and slow reaction start-up in conventional bioleaching oxidation.

[0020] 2. Shorten the leaching cycle: The oxidation triggering unit can activate the mineral interface in advance, promoting the rapid entry of subsequent acid-complexing microorganisms, surfactant-producing bacteria and XS6-1 into the effective leaching state, thus shortening the leaching cycle from the conventional biological leaching process, which usually takes more than 30 days (or even 120 days), to 2-15 days, thereby improving process efficiency.

[0021] 3. Reduced use of chemical reagents: Leaching is driven by the in-situ generation of low-concentration oxidants, organic acids, complexing ligands and surfactants by microorganisms, eliminating the need for large amounts of strong acids or strong oxidants. This reduces acid consumption, oxidant consumption and equipment corrosion risk, and significantly lowers the acidity and salt load of the leaching tail liquid, making subsequent treatment easier.

[0022] 4. Enhanced system stability and controllability: The leaching effect of the multi-strain mixed system (example) is significantly better than that of the comparative example which lacks specific functional bacteria. This indicates that the present invention is not a simple superposition of strains, but a synergistic system that relies on clear functional division and temporal coupling. It avoids substrate competition, metabolic inhibition or interface passivation caused by simple mixing of bacteria. Moreover, the metabolic complementarity between multiple strains enhances the adaptability to complex and extreme environments. The reaction process is more stable, controllable and suitable for scale-up.

[0023] 5. Improved Multi-Metal Synergistic Leaching Efficiency: Oxidation triggering units promote uranium valence state transformation, acid-producing-complexing microorganisms promote mineral lattice disruption and metal complex migration, surfactant-producing bacteria enhance ore porosity permeability, and XS6-1 enables directional identification and localized oxidation leaching of uranium minerals. After coupling of these multiple mechanisms, simultaneous release of uranium and associated metals such as molybdenum, copper, cobalt, vanadium, nickel, zinc, and rare earth elements can be achieved under unified conditions.

[0024] 6. Applicable to the development of complex ores and low-grade resources: It can effectively improve the utilization efficiency of refractory and low-grade ores and expand the application scope of bio-metallurgical technology. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 The images shown are scanning electron microscope (SEM) images of the morphological evolution of uranium-molybdenum polymetallic ore during leaching in Example 2. A: SEM image of the mineral morphology before leaching; B: Backscattered image corresponding to image A; C: SEM image of the mineral morphology 15 days after leaching; D: Backscattered image corresponding to image C. Detailed Implementation

[0027] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Unless otherwise specified, the experimental materials used in the following embodiments can be obtained commercially.

[0028] Existing uranium leaching processes and pure bioleaching technologies have some shortcomings, mainly including the following aspects: (1) The problem of high cost and heavy environmental burden of strong acid-strong oxidant system: Traditional chemical leaching relies on high concentration of acid (10-100 kg H2SO4 / t ore, mass ratio 1%-10%) and strong oxidant (1-5 kg ​​H2O2 / t ore, mass ratio 0.1%-0.5%), resulting in high acid consumption, serious equipment corrosion, high tail liquid salinity, increased difficulty of subsequent treatment, and high environmental treatment costs.

[0029] (2) Problems of insufficient oxidation capacity and long induction period of conventional biological leaching: The direct oxidation capacity of microorganisms to U(IV) in current industrial applications and literature reports is limited. The leaching system often has a long induction period, usually requiring 30 days or even more than 120 days to achieve a high leaching rate, which limits industrial applications.

[0030] (3) Problem of low synergistic leaching efficiency in complex polymetallic systems: In uranium-polymetallic associated minerals such as U-Mo, U-Cu, U-Co, and U-REE, the redox potentials of different metals are very different, and it is difficult to achieve synergistic leaching in the same system using a single technology.

[0031] (4) Problems of passivation and limited mass transfer at the ore interface: Calcium / iron salt precipitates or biofilm residues are easily formed on the ore surface, which hinders the leaching agent from penetrating into the deep mineral layer, resulting in a significant decrease in the reaction rate in the later stage.

[0032] This invention proposes a microbial ensemble for uranium and associated metal leaching, comprising an oxidation triggering unit and a bioleaching unit. The oxidation triggering unit includes iron-cycling microorganisms and hydrogen peroxide-producing bacteria. After the oxidation triggering environment is established (i.e., the system's redox potential Eh rises to 200-650 mV), the bioleaching unit further functions. The ratio of iron-cycling microorganisms, hydrogen peroxide-producing bacteria, acid-producing-complexing microorganisms, surfactant-producing bacteria, and *Microbacterium rubrum* XS6-1 is (0.5-3):(0.5-3):(1-5):(1-5):(1-5).

[0033] Iron-circulating microorganisms are used to drive Fe 2+ / Fe 3+ The redox cycle between them increases the redox potential (Eh) of the system, thereby forming a stable oxidizing environment at the mineral interface, promoting the conversion of U(IV) to U(VI) in uranium minerals, and providing favorable oxidizing conditions for subsequent bioleaching processes. Preferably, one or more of the following are selected: *Dizzyella spp.*, *Geotrichum spp.*, *Pterygospermum spp.*, *Thiobacillus*, *Leptospira*, *Festobacillus*, *Acid Microbes*, and *Bacillus sulfideus*.

[0034] Iron-cycling microorganisms can participate in the Fe metabolism process. 2+ oxidation or Fe 3+The reduction reaction of Fe maintains a continuous iron cycle within the system. During this process, Fe... 3+ It can act as an indirect oxidizing agent to promote the oxidation and release of uranium and associated metal elements in mineral lattices. Meanwhile, Fe... 2+ In the presence of trace amounts of H2O2 (generated by hydrogen peroxide-producing bacteria), a mild biological Fenton reaction system can be formed. The resulting reactive oxygen species (ROS species, such as hydroxyl radicals •OH) participate in the destruction of mineral structures under controlled conditions, promoting the continuous dissolution of uranium and its associated metals.

[0035] Hydrogen peroxide-producing bacteria are used to continuously generate low concentrations of H2O2 during metabolism, thereby creating a mild reactive oxygen species environment in the system and promoting the initial oxidative activation of mineral structures. Preferably, one or more of the following are selected: Lactobacillus, Streptococcus, Staphylococcus, Hydrogenophilic bacteria, and Vibrio violaceus.

[0036] Hydrogen peroxide-producing bacteria continuously release low concentrations of H2O2 during their metabolism. This substance can participate in the formation of mild reactive oxygen species (ROS) in the system, oxidizing the surface structure of minerals and thus promoting the conversion of U(IV) to U(VI) in uranium minerals. Simultaneously, in the presence of iron-cycling microorganisms, the Fe in the system... 2+ / Fe 3+ Cycling can further enhance the stability of the reactive oxygen species environment, thereby creating continuous oxidation-driven conditions at the mineral interface, shortening the induction period of bioleaching, and improving the leaching efficiency of uranium and its associated metals.

[0037] Acid-producing and complexing microorganisms secrete metabolic products such as organic acids and metal complexing ligands. Through acid hydrolysis and complexation, they promote the cleavage of uranium-polymetallic mineral structures, destroy the mineral lattice structure, and stabilize and dissolve metal ions. They are preferably one or more of the following: *Arthrobacter*, *Amycosis*, *Cladosporium*, *Morchella*, *Penicillium*, *Syntrophus*, *Pandora*, and *Massezia*.

[0038] Organic complexing ligands (containing organic acids) secreted by acid-producing and complexing microorganisms have multiple functions: providing H+. + Maintaining an acidic environment; with UO2 2+ Cu 2+ Co 2+ This process forms stable complexes, preventing metal ions from hydrolyzing or undergoing secondary precipitation due to local pH fluctuations, thereby maintaining a high leaching rate; through complexation of Fe... 2+ / Fe 3+ Inhibits iron ion hydrolysis and precipitation, maintains Fe 2+ / Fe 3+The cycle enhances the continuous activation capacity of the bio-Fenton system for the uranium-polymetallic ore interface; it also slows down the continuous oxidation capacity of H2O2 generated by hydrogen peroxide-producing bacteria, allowing low-dose H2O2 to maximize the redox potential of the system in the oxidation triggering unit.

[0039] Surfactant-producing bacteria are used to produce biosurfactants such as rhamnolipids, trehalolipids, and sophorol to reduce the interfacial tension of the ore, improve the permeability of the leachate to the ore pores and microcracks, and enhance the contact efficiency between the ore and the leachate. Preferably, they are one or more of the following: Gordonella, Saxonymus, Ustilago maydis, Trichomonas vaginalis, Agrobacterium, Sphingosine monocytogenes, Oligotrophus, Rifonsonia, and Mycobacterium.

[0040] The biosurfactants produced by surfactant-producing bacteria have excellent wetting and emulsifying effects, which can reduce the surface tension of uranium-polymetallic ores. Microorganisms produce extracellular polysaccharides or proteins to peel off calcium / iron salt precipitates and biofilms from the ore surface, and enhance the permeability of the leachate to microfractures. Therefore, unreacted areas inside the ore are continuously exposed to the leaching environment, avoiding rate decay in the later stages of the reaction.

[0041] Specific uranium recognition-oxidizing microorganism: Brick-red Microbacterium XS6-1 ( Microbacterium Testaceum XS6-1 is used to specifically identify uranium-polymetallic minerals, specifically capture or adsorb on or around the surface of uranium-polymetallic minerals, and efficiently oxidize and leach uranium and associated mineral resources.

[0042] Specific uranium recognition-oxidizing microorganisms can form a directional attachment layer on the surface of uranium minerals, creating a locally high-concentration metabolically active zone; stabilizing the redox microenvironment; and utilizing short-distance electron transport pathways. This enhances U(IV) oxidation efficiency and promotes the simultaneous dissolution of associated metals.

[0043] A method for leaching uranium and associated metals, utilizing the aforementioned microbial combination for leaching to obtain uranium and associated metals, includes the following steps: Step 1: Crush the ore containing uranium and associated metals to a particle size of 0.5-10 mm. The associated metals are one or more of molybdenum, vanadium, copper, cobalt, zinc, lead, nickel, germanium, tellurium, selenium, or rare earth elements, such as complex associated minerals like U-Mo, U-Cu, U-Co, U-Cu-Co, and U-REE.

[0044] Step 2: Add a bacterial solution containing oxidation triggering units to the ore. The oxidation triggering units include iron-circulating microorganisms and hydrogen peroxide-producing bacteria. After reacting for 2-6 hours, an oxidation triggering environment is established in the system, increasing the oxidation-reduction potential of the system to 200-650mV.

[0045] Step 3: After the oxidizing environment is formed, add a bacterial solution containing bioleaching units to the reaction system. The bioleaching units include acid-producing-complexing microorganisms, surfactant-producing bacteria, and specific uranium recognition-oxidizing reddish-brown microbacterium XS6-1. First, add the acid-producing-complexing microorganisms and react for 2-4 hours, then inoculate with surfactant-producing bacteria and continue the reaction for 0.5-3 hours, and finally inoculate with specific uranium recognition-oxidizing reddish-brown microbacterium XS6-1.

[0046] Step 4: Maintain the system pH at 2.0-7.0 and the temperature at 15-40℃ for leaching reaction, with a cycle of 2-15 days. Efficient and synergistic leaching of multi-metal resources is achieved through mild bio-oxidation triggering, bio-acidification and complexation cleavage, surfactant-enhanced penetration, and microbial targeted attachment oxidation.

[0047] The core of this invention lies in constructing a "bio-coordinated oxidation-leaching mechanism" that triggers oxidation and amplifies leaching. By synergistically defining the types, proportions, sequences, and time intervals of microbial strains, a stable, efficient, and sustainable oxidation-complexation microenvironment is formed at the mineral interface, achieving the synergistic leaching of uranium and its associated metals. The synergistic oxidation mechanism includes the following intercoupled processes: 1. Biological oxidation triggering phase (rapid Eh increase phase) In the initial stages of the reaction, a mild biological oxidant, namely iron-cycling microorganisms and hydrogen peroxide-producing bacteria, is introduced into the system. The iron-cycling microorganisms drive the Fe... 2+ / Fe 3+ The redox cycle between Fe 3+ It can act as an oxidizing agent to promote the oxidative release of U(IV) and associated metal elements: Fe 2+ → Fe 3+ Fe 3+ + U(IV) → Fe 2+ + U(VI).

[0048] Hydrogen peroxide-producing bacteria continuously release low concentrations of H2O2 during their metabolism. H2O2 can directly oxidize U(IV) or react with Fe. 2+ A bio-Fenton reaction system is formed, generating Fe. 3+ And •OH re-oxidation of U(IV): H2O2+ U(IV) → H2O + U(VI), Fe 2+ + H2O2→ Fe 3+ + •OH + OH - , •OH + U(IV) →H2O + U(VI).

[0049] The continuously generated reactive oxygen species (ROS) create a mild oxidizing environment in the system, rapidly increasing the local redox potential and maintaining the system's Eh value within the 200-650 mV range. Within this Eh range, reactive oxygen species rapidly attack the uranium-polymetallic mineral structure, promoting the conversion of U(IV) to U(VI) in uranium minerals, releasing uranium and associated mineral resources; Fe 3+ It can act as an indirect oxidant to further participate in the electron transfer reaction on the mineral surface and establish favorable oxidation conditions for subsequent bioleaching processes. It is worth noting that because the dosage of the bio-generated oxidant H2O2 is low, it does not form an excessive accumulation of free radicals, thus avoiding significant toxicity to microorganisms.

[0050] This stage acts like a "fuze," used to overcome the bottleneck of limited oxidation rate in conventional bioleaching systems (i.e., bioleaching units); at the same time, the concentration of oxidants produced by the organisms is controlled at a low level to avoid significant inhibition of microorganisms.

[0051] 2. Microbial metabolic enhancement stage (bioscale-up stage) After the formation of a mild oxidizing environment, the multi-species system enters a metabolically active state: (1) acid-producing and complexing microorganisms secrete organic acids such as oxalic acid, citric acid, gluconic acid, succinic acid, and malic acid, which lower the local pH and promote the loosening of the mineral lattice structure; (2) organic acids and iron carriers affect U(VI) and Cu 2+ Co 2+ MoO4 2- Rare earth ions and other rare earth ions form complexes, which improve the solubility of metal resources; (3) Organic complex ligands inhibit the hydrolysis and precipitation of iron ions, and maintain Fe 2+ / Fe 3+ (3) The cycle enhances the continuous activation ability of the biological Fenton system for the uranium-polymetallic ore interface; (4) Surfactants reduce the interfacial tension between ore and solution, passivate the surface of glassy ore, and improve the permeability of leaching agents to ore pores; (5) Microorganisms enhance the activity of electron transport chains under moderate oxidative conditions, accelerating the redox cycle; (6) Specific uranium recognition-oxidizing microorganisms (brick-red microbacteria) Microbacterium Testaceum XS6-1 specifically captures / adsorbs around uranium minerals, efficiently oxidizing U(IV) to U(VI), thus promoting the leaching of uranium and associated mineral resources.

[0052] This stage is characterized by the kinetic synergistic effect of "chemical triggering-biological amplification".

[0053] 3. Microenvironment construction and interface enhancement mechanisms The following three-layer microenvironment is formed on the surface of mineral particles: the first layer is the microbial attachment and wetting layer, the second layer is the organic acid and complexing agent enrichment layer, and the third layer is the local high Eh oxidation layer.

[0054] This structure helps to: improve electron transfer efficiency; shorten diffusion paths; enhance mineral surface reaction rates; and achieve directional leaching rather than disordered dissolution.

[0055] 4. Multi-metal synergistic dissolution mechanism Under the aforementioned synergistic system: uranium preferentially dissolves in its U(VI) complex state; associated metals such as copper, cobalt, and nickel are released simultaneously under acidic complexing conditions; molybdenum and rare earth elements enter the solution as anionic complexes. By synergistically limiting the types, proportions, order, and time intervals of microbial species, a stable, efficient, and sustainable oxidation-complexing microenvironment is formed at the mineral interface, achieving the synergistic leaching of uranium and its associated metals.

[0056] This invention establishes a multi-level synergistic mechanism of oxidation-leaching with "mild triggering + metabolic amplification". Its essence is to achieve a balance between reaction rate enhancement and ecological safety by constructing a controllable redox window without relying on strong oxidants.

[0057] Example 1 This embodiment uses hard-rock uranium-molybdenum polymetallic ore as the research object and conducts a 15-day leaching experiment. In this embodiment, the iron-circulating microorganism is a fermentation-based microorganism (…). Geothrix fermentans DSM 14018 was purchased from the German Microbial Culture Collection Center; the hydrogen peroxide producing bacterium was *Lactobacillus curlis* (…). Lactobacillus crispatus GDMCC1.4925 was purchased from the Guangdong Provincial Microbial Culture Collection Center; the acid-producing-complexing microorganism was Cladosporium buddingii (GDMCC1.4925). Cladosporium cladosporioides CICC 41760 was purchased from the China Industrial Microbial Culture Collection Center; the surfactant-producing bacterium was *Rifonsella rivastigmoides*. Leifsonia sp. CICC 25134 was purchased from the China Industrial Microbial Culture Collection Center; the specific uranium-recognizing bacterium was Brick Red Microbacterium XS6-1 ( Microbacterium testaceum XS6-1CGMCC 28318) is deposited at the China General Microbiological Culture Collection Center. (Fermentation site) G. fermentans Lactobacillus curvature L. crispatus , Cladosporium cladosporum C. cladosporioides, Rifons Leifsonia sp. and brick-red microbacteria M. testaceum The volume ratio of XS6-1 is 1:3:2:1:5.

[0058] 1. Material preparation: Select 1 kg of hard rock uranium-molybdenum polymetallic ore containing 0.15% U and 0.08% Mo, crush it to a particle size of 4 mm, and prepare a 1 L suspension.

[0059] 2. Inoculation with bacterial culture containing oxidation triggering units: First, inoculate with bacterial culture containing oxidation triggering units, including iron-circulating microorganisms (fermentation-based microbial culture). Geothrix fermentans ) and hydrogen peroxide-producing bacteria (Lactobacillus curvature) Lactobacillus curly The initial density of each strain was 10. 7 -10 8 CFU / mL, pre-reaction for 5 hours to create an oxidation-triggered environment.

[0060] 3. Inoculation with the bioleaching unit: When the system's redox potential Eh rises to 200-650 mV, add the bacterial solution containing the bioleaching unit to the reaction system, starting with acid-producing complexing microorganisms (Bacillus buddingus). Cladosporium cladosporioides After reacting for 3 hours, the bacteria that produce surfactant (Rifsonella) were inoculated. Leifsonia The reaction continued for 1 hour, and finally, the bacteria were inoculated with specific uranium-recognizing, brick-red oxidizing microbacterium XS6-1 (sp.). Microbacterium testaceum XS6-1), with an initial density of 10 per strain. 7 -10 8 CFU / mL.

[0061] 4. Operation: The initial pH was set to 5.0, the temperature was kept constant at 15°C, and the reaction was continued for 15 days.

[0062] 5. Monitoring: During the reaction, the pH fluctuation range was maintained between 2.7 and 5.0, there was no sludge blockage, the system had good fluidity, and the leaching results of U and Mo are shown in Table 1.

[0063] Table 1

[0064] Conclusion and Analysis: The sequential synergistic system of "oxidation triggering unit + bioleaching unit" constructed in this invention can rapidly initiate the leaching process of U-Mo polymetallic ores. In the initial stage of the reaction, the system pH was 5.0, Eh was only +49mV, and no significant release of uranium or molybdenum was detected in the leachate. Five hours after inoculation with fermenting *Lactobacillus thuringiensis* and *Lactobacillus curlis*, the system pH rapidly decreased to 3.5, Eh increased to +281 mV, and the uranium concentration reached 51 mg / L and the molybdenum concentration reached 24 mg / L, indicating that the oxidation triggering unit had established an effective redox environment in a short time and initially activated the mineral interface.

[0065] After entering the bioleaching stage, the concentrations of uranium and molybdenum rapidly increased with the sequential inoculation of *Cladosporium budscens*, *Rifonsonia*, and XS6-1. After one day of reaction, the uranium concentration reached 253 mg / L and the molybdenum concentration reached 129 mg / L; after five days, the uranium concentration rapidly increased to 1362 mg / L and the molybdenum concentration to 718 mg / L, indicating that acid formation-complexation, surfactant penetration, and the directional adhesion of XS6-1 jointly promoted the rapid dissolution of uranium-molybdenum minerals. After 10 days of reaction, the uranium and molybdenum concentrations reached 1443 mg / L and 751 mg / L, respectively; after 15 days, they were 1427 mg / L and 754 mg / L, respectively, showing a general stabilization, indicating that the main leached uranium and molybdenum components had been largely released.

[0066] The changes in pH and Eh showed that the system rapidly transitioned from low to high Eh within 5 hours, and subsequently maintained a stable Eh between +355mV and +393mV. This indicates that the oxidation triggering unit did not cause a strong oxidative shock, but rather created a mild oxidation window suitable for subsequent bioleaching. The pH stabilized after decreasing from 5.0 to 2.3-2.5, indicating that the acid-producing-complexing microorganisms could continuously provide an acidolytic and complexing environment without severe acidification or sludge blockage. These results demonstrate that the system of this invention can achieve rapid, efficient, and stable leaching of U-Mo polymetallic ores within 15 days (10 days).

[0067] Example 2 The results of monitoring ore-microorganism interactions and ore morphology during the bioleaching process of uranium-molybdenum polymetallic ore in Example 1 are as follows: Figure 1 As shown.

[0068] Conclusion and analysis: Uranium-molybdenum polymetallic ores underwent significant morphological evolution during bioleaching, indicating that the microbial assemblage of the present invention can effectively act on the ore interface and promote the release of uranium and molybdenum through multiple mechanisms such as oxidation triggering, acid hydrolysis complexation, interface enhancement, and directional attachment.

[0069] In the initial stage of the reaction (t=0d), secondary electron imaging and backscattering imaging showed that the overall structure of the ore particles was relatively intact, with clear particle boundaries and a flaky or blocky surface. Although natural cracks and layered textures existed locally, the overall density was strong, and no obvious pores, erosion pits, or large amounts of debris were observed. The relatively concentrated distribution of mineral brightness in backscattering imaging indicated that before the reaction, high atomic number elements or metallic mineral components in the ore were still mainly located within the mineral matrix and had not yet undergone significant migration or interface reconstruction. After 15 days of reaction, the ore surface morphology changed significantly. Secondary electron imaging showed that the surface of the ore particles changed from a relatively dense and flat blocky structure to a rough, porous, broken, and flaky state. Obvious disintegration appeared at the particle edges, and a large amount of fine debris and flocculent and flaky material adhered to the surface, indicating that the mineral lattice was continuously damaged during leaching, and the ore particles underwent surface erosion, crack propagation, and local dissociation. This phenomenon indicates that the organic acids and complexing ligands produced by acid-producing and complexing microorganisms can promote mineral surface dissolution, while surfactant-producing bacteria can enhance the penetration of the leachate into the microcracks and pores of the ore, thereby continuously exposing the reaction interfaces inside the mineral. Backscatter imaging further reveals that the contrast between light and dark areas on the leached ore surface is more complex, with high-brightness areas exhibiting discontinuous patchy or granular distribution, and localized significant fragmentation and redistribution characteristics. This suggests that during the leaching process, uranium-containing, molybdenum-containing, or other high-atomic-number metal components undergo interfacial migration, dissolution, and localized redeposition / residue, while new reaction products or microbial-mineral complex interfaces are formed on the mineral surface. Compared to the initial sample, the dense structure of the ore particles after the reaction is significantly disrupted, with an increase in surface active sites and more developed mass transfer channels, which is conducive to the further release of uranium and molybdenum from the mineral lattice or encapsulated phases.

[0070] Example 3 This embodiment uses hard-rock U-Cu-Co polymetallic ore as the research object and conducts a 15-day leaching experiment. In this embodiment, the iron-circulating microorganism is Leptospira ironophila (…). Leptospirillum ferriphilum DSM14647 was purchased from the German Microbial Culture Collection Center; the hydrogen peroxide-producing bacterium was *Gluconobacterium oxychloride* (DSM14647). Gluconobacter oxidans ATCC 23771) was purchased from the American Center for Type Culture Collection; the acid-producing-complexing microorganism was *Penicillium wannii*. Paecilomyces variotii CCTCC AF 2019001) was purchased from the China Center for Type Culture Collection; the surfactant-producing bacteria was *Oligotrophomonas rhizophila* (CCTCC AF 2019001). Stenotrophomonas rhizophila ATCC BAA-473 was purchased from the American Center for Type Culture Collection; the specific uranium-recognizing bacterium was Brick Red Microbacterium XS6-1 ( Microbacterium testaceum XS6-1 (CGMCC 28318) is deposited at the China General Microbiological Culture Collection Center. *Leptospira ferrophila* L. ferriphilumGlucosamine oxidase G. oxydans Penicillium wansii P. colorful Oligotrophic rhizobia S. rhizophila and brick-red microbacteria M. testaceum The volume ratio of XS6-1 is 3:1:1:1:1.

[0071] 1. Material preparation: Select 1 kg of hard rock uranium ore containing 0.17% U, 0.16% Cu and 0.11% Co, crush it to a particle size of 4 mm, and prepare 1 L of suspension.

[0072] 2. Inoculate with bacterial suspension containing oxidation triggering units: First, inoculate with bacterial suspension containing oxidation triggering units, including iron-circulating microorganisms (Leptospira ferrophila). Leptospirillum ferriphilum ) and hydrogen peroxide-producing bacteria (Gluconobacterium oxidans) Gluconobacter oxidans The initial density of each strain was 10. 7 -10 8 CFU / mL, pre-reaction for 6 hours to create an oxidation-triggered environment.

[0073] 3. Inoculation with the bioleaching unit: When the system's redox potential Eh rises to 200-650 mV, add the bacterial solution containing the bioleaching unit to the reaction system, starting with acid-producing complexing microorganisms (e.g., *Paecilomyces wani*). Paecilomyces colorful After reacting for 4 hours, the bacteria that produce the surfactant (Oligotrophomonas rhizophila) were inoculated. Stenotrophomonas rhizophilous Continue the reaction for 3 hours, and finally inoculate with specific uranium-recognizing-oxidizing brick-red microbacterium XS6-1 ( Microbacterium testaceum XS6-1), with an initial density of 10 per strain. 7 -10 8 CFU / mL.

[0074] 4. Operation: The initial pH was set to 4.0, the temperature was kept constant at 40°C, and the reaction was continued for 15 days.

[0075] 5. Monitoring: During the reaction, the pH fluctuation range was maintained between 2.7 and 5.0, there was no sludge blockage, the system had good fluidity, and the leaching results of U, Cu and Co are shown in Table 2.

[0076] Table 2

[0077] Conclusion Analysis: After replacing the iron-circulating microorganisms, hydrogen peroxide-producing bacteria, acid-complexing microorganisms, and surfactant-producing bacteria in Example 1 with similar functional microorganisms, the sequential synergistic system of "oxidation triggering unit + bioleaching unit" described in this invention can still achieve efficient synergistic leaching of uranium, copper, and cobalt in U-Cu-Co polymetallic ores. This indicates that the technical effect of this invention does not depend on a single strain, but mainly on the metabolic division of labor, sequential inoculation, and interfacial synergistic effects among the functional microorganisms.

[0078] Initially, the system pH was 4.0, Eh was +73 mV, and the concentrations of uranium, copper, and cobalt were all 0. After 6 hours of oxidation triggering, Eh rapidly increased to +481 mV, and the concentrations of uranium, copper, and cobalt reached 41 mg / L, 34 mg / L, and 27 mg / L, respectively. This indicates that *Leptospira ferrophila* and *Glucobacterium oxidans* can rapidly construct a high-Eh oxidation environment, generating initial oxidation activation of uranium and associated copper and cobalt minerals. During the bioleaching stage, acid-producing-complexing microorganisms, surfactant-producing bacteria, and XS6-1 were added sequentially, causing metal release to enter a rapid growth phase. On day 1 of reaction, the concentrations of uranium, copper, and cobalt reached 265 mg / L, 247 mg / L, and 158 mg / L, respectively; on day 5, they increased to 1256 mg / L, 1108 mg / L, and 794 mg / L, respectively; and on day 10, they further increased to 1649 mg / L, 1542 mg / L, and 1049 mg / L, respectively. This indicates that the system not only promotes the oxidative leaching of uranium but also simultaneously promotes the release of associated copper and cobalt metals through acidolysis, complexation, and interfacial permeation. From day 10 to day 15 of reaction, the concentrations of uranium, copper, and cobalt fluctuated relatively little, indicating that the leaching process gradually reached a plateau. The pH fluctuated stably between 2.2 and 2.5, and Eh remained between +393 mV and +462 mV, indicating that the reaction system maintained a stable acidic complexation environment and redox conditions in the middle and later stages. This embodiment demonstrates that the present invention is not only applicable to the U-Mo system, but also to complex polymetallic associated uranium ores such as U-Cu-Co, and has good ore adaptability and polymetallic synergistic leaching capability.

[0079] Experiment 1 This experiment used hard-rock uranium-molybdenum polymetallic ore as the subject and conducted a 15-day comparative experiment. Comparative Examples 1 to 4 are shown in Table 3, and the remaining experimental procedures are the same as in Example 1.

[0080] Table 3

[0081] The operating conditions were the same as in Example 1. After the reaction was completed, the leachate was taken, the concentrations of uranium and molybdenum were measured, and the uranium and molybdenum leaching rates were calculated, as shown in Table 4.

[0082] Table 4

[0083] Conclusion and Analysis: The uranium leaching rate of the complete system in Example 1 was 95.1%, and the molybdenum leaching rate was 94.3%, both significantly higher than those of the comparative examples, indicating a clear synergistic effect between the oxidation triggering unit and the bioleaching unit. Comparative Example 1, which only retained the oxidation triggering unit, had uranium and molybdenum leaching rates of 37.2% and 26.1%, respectively. This indicates that although iron-circulating microorganisms and hydrogen peroxide-producing bacteria can increase the system's Eh and promote some mineral oxidation, the lack of subsequent acid hydrolysis complexation, surfactant mass transfer enhancement, and XS6-1 directional leaching makes it difficult to achieve efficient leaching.

[0084] Comparative Example 2, which only retained the bioleaching unit, achieved uranium and molybdenum leaching rates of 64.7% and 52.5%, respectively, which were higher than those of the oxidation triggering unit alone, but still significantly lower than those of Example 1. This indicates that acid-producing-complexing microorganisms, surfactant-producing bacteria, and XS6-1 can promote mineral dissolution and metal release, but without a pre-oxidation triggering environment, the system's start-up rate and U(IV) oxidation efficiency are insufficient, limiting the upper limit of leaching.

[0085] Comparative Example 3 used externally added H2O2 and FeCl2 to replace the oxidation triggering unit and combined it with the bioleaching unit. The uranium and molybdenum leaching rates were 53.6% and 57.4%, respectively, which were lower than those in Example 1. This indicates that simply adding chemical oxidants is insufficient to simulate the in-situ continuous generation of low concentrations of H2O2 and FeCl2 by microorganisms. 2+ / Fe 3+ The process involves a dynamic cycle and may inhibit subsequent microbial activity. Comparative Example 4, using only H₂O₂ and FeCl₂, showed the lowest uranium and molybdenum leaching rates, at 22.8% and 21.7%, respectively, further demonstrating that simple chemical oxidation triggering is insufficient for efficient co-leaching of complex uranium-molybdenum ores. These results prove that the advantage of this invention does not stem solely from the oxidant or simple bioleaching, but rather from the temporal synergy between the oxidation triggering unit and the bioleaching unit.

[0086] Experiment 2 This experiment used hard-rock uranium-molybdenum polymetallic ore as the research object and conducted a 15-day comparative experiment. Comparative examples 5 to 12 are shown in Table 5, and the remaining experimental procedures are the same as in Example 1. The compound microorganisms used in this experiment are the same as those in Example 1, the only difference being the dosage ratio of each strain.

[0087] Table 5

[0088] The operating conditions were the same as in Example 1. After the reaction was completed, the leachate was taken, the concentrations of uranium and molybdenum were measured, and the uranium and molybdenum leaching rates were calculated, as shown in Table 6.

[0089] Table 6

[0090] Conclusion Analysis: The ratio of bacterial strains added has a significant impact on the uranium and molybdenum leaching effects. In Example 1, the volume ratio of the fermentation-initiated bacteria to Lactobacillus curvature in the oxidation triggering unit was 1:5, and the volume ratio of Cladosporium buddingii, Rifonsonia spp., and XS6-1 in the bioleaching unit was 2:1:5. Under this ratio, the uranium leaching rate reached 91.3%, and the molybdenum leaching rate reached 89.1%, demonstrating the best synergistic effect.

[0091] Comparative Examples 5 and 6, by altering the relative proportions of the two types of bacteria in the oxidation triggering unit, significantly decreased the uranium and molybdenum leaching rates. In Comparative Example 5, the excessively high proportion of hydrogen peroxide-producing bacteria may lead to excessive localized reactive oxygen species accumulation, causing oxidative stress on subsequent functional bacteria; in Comparative Example 6, the excessively high proportion of iron-cycling microorganisms may result in insufficient H2O2 supply and Fe... 2+ / Fe 3+ The mismatch between the iron cycle and the generation of reactive oxygen species reduces the oxidation triggering efficiency. This indicates that the iron cycle and H2O2 generation processes in the oxidation triggering unit need to be maintained in a proper balance.

[0092] Comparative Examples 7 to 9, lacking acid-producing complexing microorganisms, surfactant-producing bacteria, or XS6-1 respectively, showed significantly lower leaching efficiency than Example 1. Specifically, Comparative Example 7, lacking acid-producing complexing microorganisms, saw uranium and molybdenum leaching rates decrease to 55.8% and 52.6%, respectively. This indicates that while the system still exhibits oxidation triggering, interface strengthening, and XS6-1 orientation effects after the absence of acid-producing complexing microorganisms, the mineral lattice acidification, metal complexation migration, and Fe... 2+ / Fe 3+ Insufficient stable circulation capacity significantly limited the release of uranium and molybdenum. Comparative Example 8 shows that the absence of surfactant-producing bacteria reduced the wettability of ore particle surfaces, microfracture penetration, and passivation layer stripping ability, making it difficult for leachate and microbial metabolites to fully penetrate the mineral interior, thus reducing the uranium and molybdenum leaching rates. In Comparative Example 9, the absence of XS6-1 resulted in a uranium leaching rate of 49.6%, the lowest among the single-bacterial deletion groups, indicating that the specific uranium-recognizing-oxidizing red bacillus XS6-1 plays a crucial role in the directional attachment, local oxidation, and uranium release of uranium minerals; simultaneously, the molybdenum leaching rate also decreased to 50.2%, indicating that the local activation environment formed by XS6-1 also promotes the synergistic release of associated molybdenum.

[0093] In Comparative Examples 10 to 12, the leaching rate decreased after the proportions of acid-producing-complexing microorganisms, surfactant-producing bacteria, or XS6-1 were reduced. This indicates that even if functional bacteria are not completely absent, insufficient proportions of key functional bacteria will limit the complete functioning of the synergistic chain. This result proves that the functional bacteria in this invention are not arbitrarily combined, but need to work together within a specific proportion range to form a stable and efficient leaching system.

[0094] Experiment 3 This experiment used hard-rock uranium-molybdenum polymetallic ore as the research object and conducted a 15-day comparative experiment. Comparative Examples 13 to 18 are shown in Table 7, and the remaining experimental procedures are the same as in Example 1. The composite microorganisms used in this experiment are the same as in Example 1, the only difference being the reaction interval between inoculations of each strain.

[0095] Table 7

[0096] The operating conditions were the same as in Example 1. After the reaction was completed, the leachate was taken, the concentrations of uranium and molybdenum were measured, and the uranium and molybdenum leaching rates were calculated, as shown in Table 8.

[0097] Table 8

[0098] Conclusion: The inoculation interval of the strains has a significant impact on the leaching effect of U-Mo polymetallic ores. In Example 1, the oxidation triggering unit was activated for 5 hours, the interval between the acid-producing-complexing microorganism and the surfactant-producing microorganism was 3 hours, and the interval between the surfactant-producing microorganism and XS6-1 was 1 hour. Under these conditions, the leaching rates of uranium and molybdenum reached 91.3% and 89.1%, respectively, which were the best results of this experiment.

[0099] In Comparative Example 13, the oxidation triggering unit's action time was only 0.5 hours, and the uranium and molybdenum leaching rates decreased to 68.4% and 63.7%, respectively. This indicates that when the oxidation triggering time is too short, Fe... 2+ / Fe 3+ The circulating and low-dose H2O2 reactive oxygen species environment has not been fully established, resulting in insufficient improvement in the system's Eh, which makes it difficult for the subsequent bioleaching unit to function within a suitable oxidation window. In Comparative Example 14, the oxidation triggering time was extended to 12 hours. Although the leaching rate was higher than that of Comparative Example 13, it was still lower than that of Example 1. This indicates that an excessively long oxidation triggering stage may lead to the accumulation of local oxidation products or iron salt deposits, which in turn affects subsequent microbial attachment and mass transfer.

[0100] In Comparative Example 15, surfactant-producing bacteria were added 0.5 hours after the acid-complexing microorganisms acted, resulting in a decrease in uranium and molybdenum leaching rates. This indicates that insufficient acidolysis and complexation pretreatment meant the mineral lattice was not sufficiently loosened, making it difficult for the surfactant to maximize its mass transfer enhancement effect. In Comparative Example 16, the interval was extended to 12 hours, but the leaching rate was still lower than in Example 1. This suggests that an excessively long interval may lead to localized metal hydrolysis or secondary precipitation, weakening the subsequent interfacial penetration and uranium recognition-oriented leaching effects.

[0101] In Comparative Example 17, XS6-1 was added 0.1 hours after the surfactant-producing bacteria acted, resulting in uranium and molybdenum leaching rates of 70.5% and 64.9%, respectively. This indicates that XS6-1 cannot effectively adhere to the activated uranium mineral surface before interfacial wetting and pore penetration are fully established. In Comparative Example 18, the interval was extended to 12 hours, and the leaching rate was still lower than in Example 1. This suggests that an excessively long interval may lead to excessive coverage of mineral active sites by biofilms or surface metabolites, affecting the subsequent targeted recognition by XS6-1. The above results indicate that a reasonable interval for adding bacteria is an important condition for achieving the synergistic leaching effect of this invention.

[0102] Experiment 4 This experiment used hard-rock uranium-molybdenum polymetallic ore as the research object and conducted a 15-day comparative experiment. Comparative examples 19 to 24 were set up as follows: Comparative Example 19: Fermentation starter, Lactobacillus curvaturei, Cladosporium buds, Rifsonella spp. and Microbacterium rubrum XS6-1 were added simultaneously.

[0103] Comparative Example 20: The oxidation triggering unit was the same as in Example 1. After a 5-hour pre-reaction to form an oxidation triggering environment, the bioleaching unit, including Cladosporium buddingii, Rifsonella, and Microbacillus redis XS6-1, was added simultaneously.

[0104] Comparative Example 21: The oxidation triggering unit was the same as in Example 1. In the bioleaching unit, Brick Red Microbacterium XS6-1 was added and reacted for 3 hours, followed by Rifsonella bacteria and reacted for 1 hour, and finally Cladosporium buddingus was added.

[0105] Comparative Example 22: First, inoculate the bacterial solution of the bioleaching unit in the same order as in Example 1. After reacting for 5 hours, inoculate the bacterial solution of the oxidation triggering unit in the same order as in Example 1.

[0106] Comparative Example 23: First, inoculate with the bacterial solution of the bioleaching unit, and simultaneously add Cladosporium buddingii, Rifsonella spp. and Microbacterium rubrum XS6-1. After reacting for 5 hours, inoculate with the bacterial solution of the oxidation triggering unit, and add them in the same order as in Example 1.

[0107] Comparative Example 24: The oxidation triggering unit was first added to the fermentation site and reacted for 5 hours, then Lactobacillus curvatureis was added. The bioleaching unit, Cladosporium buds, Rifsonella and Brick Red Microbacterium XS6-1 were added at the same time.

[0108] In this experiment, the same compound microorganisms as in Example 1 were used, the only difference being the order in which the strains were added.

[0109] The operating conditions were the same as in Example 1. After the reaction was completed, the leachate was taken, the concentrations of uranium and molybdenum were measured, and the uranium and molybdenum leaching rates were calculated, as shown in Table 9.

[0110] Table 9

[0111] Conclusion: The order of strain addition has a significant impact on the leaching effect of U-Mo polymetallic ores. In Example 1, the order of "oxidation triggering unit priority - acid production complexation - interface enhancement - XS6-1 directional leaching" was adopted, and the leaching rates of uranium and molybdenum reached 91.3% and 89.1%, respectively, which were significantly higher than those of the control groups adjusted by each order.

[0112] In Comparative Example 19, with the simultaneous addition of five bacterial strains, the uranium and molybdenum leaching rates were 78.6% and 72.8%, respectively, lower than in Example 1. This indicates that simple mixed addition leads to different functional bacteria competing for space and substrate simultaneously in the early stages of the reaction, making it difficult to form a clear time gradient for the oxidation triggering, acid hydrolysis and complexation, interface enhancement, and directional attachment processes. In Comparative Example 20, although the oxidation triggering unit was added preferentially, the uranium and molybdenum leaching rates were still lower than in Example 1 even with the simultaneous addition of three bacterial strains to the bioleaching unit. This indicates that the bioleaching unit also needs to sequentially complete the acid hydrolysis and complexation, interface penetration, and uranium recognition and attachment processes.

[0113] In Comparative Example 21, the addition of XS6-1 before the acid-producing-complexing microorganisms significantly reduced the leaching rates of uranium and molybdenum, indicating that XS6-1 needs to be activated by oxidation and preliminary acid hydrolysis on the mineral surface to fully exert its directional recognition and local oxidation effects. If added too early, the mineral interface is not fully exposed, making it difficult to form an effective adhesion layer. In Comparative Examples 22 and 23, the leaching rate decreased more significantly when the oxidation triggering unit was placed later, indicating that without the initial Eh enhancement and a mild reactive oxygen environment, subsequent acid hydrolysis, complexation, and surfactant action cannot be effectively converted into efficient leaching. In Comparative Example 24, the fermentation-promoting bacteria and Lactobacillus curvature were added stepwise, resulting in lower leaching rates than in Example 1, indicating that iron cycling and H2O2 generation need to be synchronously coupled in the early stages of the reaction to form a stable biological Fenton triggering environment. This experiment demonstrates that the strain addition order specified in this invention has a necessary and non-obvious synergistic effect.

[0114] The above are merely preferred embodiments of the present invention. Although the present invention has been described in detail above with general descriptions, specific embodiments, and experiments, some modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A microbial assemblages for uranium and associated metal leaching, characterized in that, include: Oxidation triggering unit: iron-cycling microorganisms and hydrogen peroxide-producing bacteria; Bioleaching unit: acid-producing-complexing microorganisms, surfactant-producing bacteria and brick-red microbacterium XS6-1 with specific uranium recognition function, wherein the acid-producing-complexing microorganisms are one or more of the following: pseudoarthrobacter, pseudoamycin, cladosporium, spore-forming fungi, penicillium, spirochetes, pandora, and muscarinic bacteria. The ratio of the amount of the iron-circulating microorganism, the hydrogen peroxide-producing bacteria, the acid-complexing microorganism, the surfactant-producing bacteria and the brick-red microbacterium XS6-1 is (0.5-3):(0.5-3):(1-5):(1-5):(1-5).

2. The microbial assemblages according to claim 1, characterized in that, The iron-circulating microorganisms are one or more of the following: Dietrichia coli, Dietrichia coli, Ironsporium galbendazim, Thiobacillus, Leptospira, Ironsporium, Acid Microbes, and Bacillus sulfide.

3. The microbial assemblages according to claim 1, characterized in that, The hydrogen peroxide producing bacteria are one or more of the following: Lactobacillus, Streptococcus, Staphylococcus, Hydrogenophilic bacteria, and Vibrio violaceus.

4. The microbial assemblages according to claim 1, characterized in that, The surfactant-producing bacteria are one or more of the following: Gordon's bacterium, Tsukumura bacterium, Ustilago maydis, Trichomonas vaginalis, Agrobacterium, Sphingosine monoclonal, Oligotrophoblastus, Rifson's bacterium, and Mycobacterium.

5. A method for leaching uranium with associated metals, characterized in that, Uranium and associated metals are obtained by leaching minerals using any of the microbial combinations described in claims 1-4.

6. The leaching method according to claim 5, characterized in that, Includes the following steps: Step 1: Crush the ore containing uranium and associated metals to a particle size of 0.5-10 mm; Step 2: Inoculate the ore with a bacterial solution containing the oxidation triggering unit, wherein the oxidation triggering unit includes the iron-circulating microorganisms and the hydrogen peroxide-producing bacteria, and pre-react for 2-6 hours to form an oxidation triggering environment; Step 3: When the redox potential Eh of the system rises to 200-650mV, add the bacterial solution containing the bioleaching unit to the reaction system. First, add the acid-producing-complexing microorganism and react for 2-4 hours. Then, inoculate the surfactant-producing bacteria and continue the reaction for 0.5-3 hours. Finally, inoculate the brick-red microbacterium XS6-1. Step 4: Maintain the pH of the system at 2.0-7.0 and the temperature at 15-40℃, and carry out the leaching reaction for 2-15 days.

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